Step 2: Navigate to your Custom Search pages
Click on Apps > Custom Search
Step 3: Click on Manage Pages next to the index page/category you would like to edit.
Step 4: You now see a list of all your pages. Click the Manage Pictures button to the right of the page you would like to edit.
Step 5: To change the order the images display change the sort order number
(sort order 1 will display first)